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authorLinus Torvalds <torvalds@linux-foundation.org>2011-02-18 11:32:28 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2011-02-18 11:32:28 -0800
commit3c18d4de86e4a7f93815c081e50e0543fa27200f (patch)
treeadea22bccd076266bf94cbda3ed6d9a98eea1206 /lib/list_debug.c
parent2a324ce7b79a3a90cc2d4ade5d5f960a99000caa (diff)
downloadlwn-3c18d4de86e4a7f93815c081e50e0543fa27200f.tar.gz
lwn-3c18d4de86e4a7f93815c081e50e0543fa27200f.zip
Expand CONFIG_DEBUG_LIST to several other list operations
When list debugging is enabled, we aim to readably show list corruption errors, and the basic list_add/list_del operations end up having extra debugging code in them to do some basic validation of the list entries. However, "list_del_init()" and "list_move[_tail]()" ended up avoiding the debug code due to how they were written. This fixes that. So the _next_ time we have list_move() problems with stale list entries, we'll hopefully have an easier time finding them.. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'lib/list_debug.c')
-rw-r--r--lib/list_debug.c39
1 files changed, 26 insertions, 13 deletions
diff --git a/lib/list_debug.c b/lib/list_debug.c
index 344c710d16ca..b8029a5583ff 100644
--- a/lib/list_debug.c
+++ b/lib/list_debug.c
@@ -35,6 +35,31 @@ void __list_add(struct list_head *new,
}
EXPORT_SYMBOL(__list_add);
+void __list_del_entry(struct list_head *entry)
+{
+ struct list_head *prev, *next;
+
+ prev = entry->prev;
+ next = entry->next;
+
+ if (WARN(next == LIST_POISON1,
+ "list_del corruption, %p->next is LIST_POISON1 (%p)\n",
+ entry, LIST_POISON1) ||
+ WARN(prev == LIST_POISON2,
+ "list_del corruption, %p->prev is LIST_POISON2 (%p)\n",
+ entry, LIST_POISON2) ||
+ WARN(prev->next != entry,
+ "list_del corruption. prev->next should be %p, "
+ "but was %p\n", entry, prev->next) ||
+ WARN(next->prev != entry,
+ "list_del corruption. next->prev should be %p, "
+ "but was %p\n", entry, next->prev))
+ return;
+
+ __list_del(prev, next);
+}
+EXPORT_SYMBOL(__list_del_entry);
+
/**
* list_del - deletes entry from list.
* @entry: the element to delete from the list.
@@ -43,19 +68,7 @@ EXPORT_SYMBOL(__list_add);
*/
void list_del(struct list_head *entry)
{
- WARN(entry->next == LIST_POISON1,
- "list_del corruption, next is LIST_POISON1 (%p)\n",
- LIST_POISON1);
- WARN(entry->next != LIST_POISON1 && entry->prev == LIST_POISON2,
- "list_del corruption, prev is LIST_POISON2 (%p)\n",
- LIST_POISON2);
- WARN(entry->prev->next != entry,
- "list_del corruption. prev->next should be %p, "
- "but was %p\n", entry, entry->prev->next);
- WARN(entry->next->prev != entry,
- "list_del corruption. next->prev should be %p, "
- "but was %p\n", entry, entry->next->prev);
- __list_del(entry->prev, entry->next);
+ __list_del_entry(entry);
entry->next = LIST_POISON1;
entry->prev = LIST_POISON2;
}